How many copies needed for remote play?

[Red Dragon]

Can you use steam remote play with just one copy of the game or do both people need to own the game?

[Green]

The one who streams it needs a copy. So only one

[JCB]

For Steam remote play, you just need one copy of a certain game.

The owner of the game can invite a user from his/hers friends list to play, as if you are both playing in local co-op.

If it isn't working, you may need to check your Steam settings, and see if Steam remote play is enabled.

EDIT: 2N was faster than me. ;)

[BlackjackGT]

Keep in mind Steam remote play has some annoying limitations in some games. In some I've played, only one of the players can use a controller, for example. (I plan to get this, but don't have it yet).

[Easy Trigger Games]

Yes, you only need one copy of the game. And both can use controllers (just go to options/controls to set it up).